1. Field of the Invention
The present invention relates to an image processing device, an image processing method, and a recording medium, and particularly, relates to a technology for performing a color mixture correction depending on the presence or absence of abnormal oblique incident light.
2. Description of the Related Art
Generally, in a single-plate type imaging element including a mosaic color filter array, color mixture occurs due to the light leakage from adjacent pixels. When an image is generated by the digital signal process of RGB color signals greatly influenced by the color mixture, the color reproducibility (image quality) of the image is deteriorated, and it is difficult to accurately calculate the WB gain for the white balance (WB) correction from the RGB signals greatly influenced by the color mixture.
Further, in the image taking of a subject image by an imaging device such as a digital camera, when strong light enters a lens, in some cases, the light reflected by the surface of an image-taking lens or macro lens is complexly reflected in the interior of the lens or the interior of the camera, and the light advancing at an unintended angle is received by an imaging element. The abnormal oblique incident light to enter the imaging element from the unintended angle in this way causes a phenomenon such as a so-called ghost or flare, and degrades the image quality of a taken image.
In particular, when the angle of the abnormal oblique incident light is large, at least some of the abnormal oblique incident light enters the photodiode of a pixel adjacent to a color filter through which it passes. When the color filter through which the abnormal oblique incident light passes does not completely correspond to the photodiode to actually receive the light in this way, the abnormal oblique incident light causes the so-called color mixture phenomenon in a large way and brings the degradation of the color reproducibility of the taken image.
As a technique for reducing the influence of the color mixture, for example, PTL 1 (Japanese Patent Application Laid-Open No. 2005-333251) discloses an imaging device to suppress the occurrence of the color noise associated with the ghost. The imaging device detects the occurrence of the color noise associated with the ghost, using RAW data, and corrects the luminance level value of pixel data for which the occurrence of the color noise is detected.
Further, PTL 2 (Japanese Patent Application Laid-Open No. 2010-130583) discloses an imaging device to enhance the accuracy of a color mixture correction process for each pixel. The imaging device stores the color mixture property information indicating the property relevant to the signal component to be mixed from a peripheral pixel to a correction target pixel, determines a correction coefficient depending on the position in a pixel array of the correction target pixel and the color mixture property information, and corrects the signal read from the correction target pixel.